Hydraulic pumping engines for coal mines, c 1850.
© Science Museum / Science & Society Picture Library
Architectural drawings in plan and elevation: top left, 'Davey's Steam and Hydraulic Pumping Engines, for Deep Shafts. The main engines force water to the surface and supply power through the column to the Hydraulic Engines. By this system the Main Engines are kept out of danger of flooding. The Hydraulic Engines will work under water, and can be actuated from the Main Engine Room'. Top right: 'Davey's Patent Hydraulic Machinery, as Applied to Collieries. The water for working the Hauling and Dip Pumping Engines is taken from the main column and returned to Sump'. Bottom: 'Davey's Patent Compound Differential Pumping Engine'. Illustration from 'Working drawings of coal mining plant' by a Derby mining engineer, John Povey Harper, published in Leeds in the 19th century.